Steam boiler



June 28,1927.

6. W. CROWELL STEAM BOILER Filed March 1, 1921 2 Sheets-Shegt l UNETE. STATES. PATENT iOFFlCE-a CHARLES \VAKEFIELD GROWELL, on SALISBURY,

Original application flied June My invention relates NORTH CAROLINA.

STEAM BOILER.

to an improvement in steam boilers, this application being division of my application, Serial; 270, filed June 19, 1920,

in the. novel construction and arconsists No, 390, and the invention rangement of parts whereby there is produced an open bottom water tube fire box with fire tubes extending from the fire box in such a way as to result in a gain in heating area of the boiler and tlue's'.

Other advantages willbe apparent from the inspection ofthe following descriptlon and the accompanying drawings in which Fig. 1 is a longitudinal sectional view of a bo lerembodymg my invention,

Figure 2 is a half secti on of the right half of the boiler taken on line 2'2 of Figure 1. Figure 3 1s a left half section taken on the line 33 of Figure l. i 'igu're 4L 1s a. right the hue H of Flgure 1 half section taken on Figure 5 is a left half section taken on the line 55 of Figure 1. Referring to the dr awings, it will be seen that have provided a boilerhaving a the box A having a suitablegrate N and a bridge wail M, a smoke box x; in

in advance of .the

a water section 11 in advance of the smoke box B and a superheater section F.

The fire-box A comprises 7 front end the tube sheet the tube sheet 43 and shell having at its :22 and at its rear end the rear head 12. The water the full length of the fire-box between the tube sheets 22 and L3, said water tubes 48 bethe cylindrical tubes 48 extend ing arranged in concentric circles, having centers coincident with tl sheet 22, and also being lines from the center irc s provided in the back 1e center of the tube arranged 1n radial of said concentric Opposite ea c-h water tube there is head-l2 hand hole 18, only one of such holes being shown the center line KK on Fig. l for the sake of clearness, whereby admission is gained for working on the tubes 4-8,

Surrounding the fire spaced therefrom, as drawings, is'the boiler sheet 21. its front 'end its $63 a -,box shell 45 and clearly shown by the sheli 9 having the tube and t e ad .7 t

suitably connected to the back head 12 of he firs-b x s ell 4: Ex ndi g between tube sheets 21 and 22am the firetubes 19.

he boil r Sh l 9 and the, re x shell 45 have each an opening in their hottoms for the reception of mud fr me so 1s secure the gra e N and the 1 at the ont end by stavs 39, tube sheet Dividfd' and this application filed March 1,

of the grate between the shells 9 and 4:5, as shown by Figs. 1 and 2. The fire tubes extend from the top of thefire-bo-x shell 45 to a point belowthe grate N and on a'line with the top of the mud frame 46. For access to the water tubes 48, the hand holes 17, only one of which is shown for the sake of clearness, are provided in the tube sheet 21', as shown by Fig. 1. Holes 14: are provided in the fire-box shell 45 to permit the circulation of water from the boiler shell to the space between the tube sheet 43 and the back head 12. Shells 9 and 45- are held together v 43 and back head 12 are lield'together by stays 15, and tube sheets 21 and are held together by the fire tubes 19 and the stays 20;

' The cylindrical form of the boiler: shell 9 and the fire-box shell i5 permits the extension of the fire-box beyond the mud frame and at thesame time provide for an open bottom fire-box and increases the heating area of the fire-box and the water tubes 4:8. Also, because of the cylindrical form of the boiler and fire-box shells, the space formerly occupied by a water leg is 'made use of in a more advantageous way to increase the heating area of the boiler by having fire tubes occupy the space formerly be clearly apparent to one skilled in the boiler art. And it will further be apparent that in my construction the size of the boiler and fire-box shells may be increased downward from the center line K-K to the point to which the water legs extend in the water leg typesof boilers. The fire-box may be as long as is found desirable and may extend beyond the mud frame 46 any suitable distance and thus provision may be made for a larger grate area than would otherwise be advantageously possible.

The the tubes extending between the fire box and the smoke box have been shown rather short but it will readily be understood that they may be of .any desired length, the tubes having been shown of short length because of the limited space available for the drawings and also for the purpose of showing how adiriission to the front end of the water tubes could be gained in case it were desired to use short tubes. struotion having a greater distance between the fire and smoke boxes, inth'e "smoke box would cause the water tubes are circularly and taken up by the water leg extension below the shell as will.

In a con the hand hole plates be unnecessary beradially aligned, as shown more clearly by Fig. 3, and it thus becomes possible for a man to go inside of the boiler, get on top of the fire tubes and have ample room to work on the front ends of the water tubes, without removing any stays, as he can find room between the stays.

In the construction so far described, the flames and gases pass from the grate N and circulate between the water tubes 48, passing over the bridge wall M and then through the fire tubes 19 into the smoke box B from which they may exit through the stack 0 when superheated steam is not desired.

The above construction may be embodied with boilers having two smoke boxes, each having a smoke stack, with a superheater section located between them and in this connection reference is made to Fig. 1 of the drawings where this construction is shown. The superheater section F is located between the smoke box B and the smoke box K in advance of the superheater section as shown. The superheater section F is cylindrical like the boiler and fire-box shells and is connected to the smoke box B by the connection head 40, as shown by Fig. 1, which is shown as a reduction head but it is obvious that the cylinder 10 of the superheater could be made the same size as the boiler shell, if it were found expedient so to do, without interfering with the principles upon which my invention is based. By male ing use of the connection head l0, it is pos sible to make. the superheater section cylindrical as described and thereby obviate unnecessary expensive construction. The superheater F is provided with a water section 11 and fire tubes which extend between the smoke boxes, as shown.

hen the superheater is in operation,the

' stack C is closed by any suitable damper C and the gases and other products of combustion pass through the superheater and into the smoke box in advance thereof and thence into the atmosphere, as will be readily under.- stood.

From the foregoing description, it will be seen that l have provided a steam boiler which has'inner and outer shells of cylindrical form and spaced apart, the inner shell, comprising a tire-box shell, having a flue sheet in its forward end with heating tubes extending therefrom in two directions, one set of tubes being fire tubes and the other set being water tubes and by extending the fire-box beyond the mud frame and occupying the space formerly taken up by a water leg by the fire tubes extending from the tube sheet a gain in heating area has been made, besides the gain made possible by the extension of the fire-box, as has hereinbefore been described. The boiler thus presented is one thatis readily and comparatively inexpensively constructed, operated and kept in repair and is adapted for high pressures and quick steaming, and is economical in fuel consumption.

Having now described my invention, what I claim and desire to secure by Letters Patent of the United States is:

1. In combination, a boiler comprising an outer cylindrical shell having an opening in the rear portion of its bottom for the reception of a grate, a mud frame surrounding said opening, a tube sheet closing the front end of said shell, a smoke box and stack in advance of said tube sheet, a back head and filling rim closing the rear end of said shell, the rim having an opening therein for the reception of the rear end of a fire box, of a cylindrical fire box of less diameter than the boiler shell and disposed with its longitudinal axis below the longitudinal axis of the boiler shell, said fire box having an opening in the rear portion of its bottom for the re- .ception of a grate, the edges of said opening resting on and being secured to the top of the mud frame, a tube sheet in the forward end of the fire box shell spaced from the mud frame, fire tubes extending between said tube sheet and the tube sheet of the boiler shell and disposed below the center of the rear tube sheet, a back head in the rear end of said fire box shell and with the back head of the boiler shell forming a water wall at the rear end of the fire box shell, and water tubes extending through the upper portion of the fire box shell and secured at their forward ends in the forward tube sheet of the fire box and at their rear ends being secured in the rear head of the fire box and communicating with said rear water wall.

2. In combination, a boiler comprising an outer cylindrical shell having an opening in the rear portion of its bottom for the reception of a grate, a mud frame surrounding said opening, a tube sheet closing the front end of said shell, a smoke box and stack in advance of'said tube sheet and a back head and filling rim closing the rear end of said shell, the rim having an opening therein for the reception of the rear end of a fire box, of a cylindrical fire box of less diameter than the boiler shell and disposed with its longitudinal axis below the longitudinal axis of the boiler shell, said fire box hav-- ing an opening in the rear portion of its bottom for the reception of a grate, the edges of said opening resting on and being secured to the top of the mud frame, a tube sheet in the forward end of the fire box shell spaced from the mud frame, fire tubes extending between said tube sheet and the tube sheet of the boiler shell and disposed below the center of the rear tube sheet, a back head in the rear end of said fire box shell and with the back head of the boiler shell formmg a water wall at the rear end of the fire box shell, and water tubes. extending through.

' o oenin restin on and the upper portion of the fire box shell and secured .at their forward ends in the forward tube sheet of the fire box, and at their rear ends being secured in the rear head of the fire box and communicating with said'water wall, said water tubes being disposed in circular and radial alignment from acenter coincident with the axial center of the tire box.

outer cylindrical shell having an opening in the rear portion of its bottom for the reception of agrate, a mud frame surrounding said opening, a tube sheet closing the front end of said shell, a smoke box and stack in advance head and filling rim closing the rear end of said shell, the rim having an opening therein for the reception of the rear end of a fire box, of a cylindrical fire box of less diameter than the boiler shell and disposed with its longitudinal axis below the longitudinal axis of the boiler shell, said fire box having an opening in the rear portion of its bottom for the reception of a grate, the edges of said i being secured to the top of the mud frame, a tube sheet in the forward end of the fire box shell spaced from the mud frame, fire tubes extending between said tube sheet and the tube sheet of the boiler shell and disposed below the center of the rear tube sheet, a back head in the rear end of said fire box shell and with the back head of the boiler shell forming a water wall at the rear end of the fire box shell, and water tubes extending through the upper portion of the fire box shell and secured at their forward ends in the forward tube sheet of the fire box and at their rear ends being secured in the rear head'of the fire box and communicating with said water wall, said water tubes being disposed in circular and radial alignment from a center coincident with the axial center of the fire box, and a group of stays extending from the front'tube sheet of the fire b x to the front tube sheet of the boiler and arranged in circular and radial alignment from the axial center of the tube sheet.

i. A cylindrical boiler, a cylindrical fire box therein having its longitudinal central axis disposed below the longitudinal central axis of the boiler, a head closing one end of the boiler, a tube sheet at the opposite end thereof and forming one wall of a smoke box disposed in advance of the boiler, the bottom of the boiler and fire box. adjacentone end, being cut away to provide a grate opening. a mud frame around said grate opening and attached to the edges of the opening in the fire box and boiler whereby the bottom of the fire box is on a level with the top' of the mud frame, a bridge wall extending'up from the bottom of the fire box and intermediate the ends thereof, water tubes extending lonjupper'portion of the fire In combination, a boiler comprising an of said tube sheet, a back gitiidinally, through the firebox and through the tube sheets thereof and disposed in the extending through the'front tube sheets of the boiler and fire' box respectively and oomniunicating with the smoke box and fire box respectively and disposed in the lower portion of the-fire box.

. 5.]The combination with a boiler comprising an out-er cylindrical shell having its forward end enclosed by atube sheet, which also forms the rear wall of a smoke box having a stack therein, the rear end of said shell being closed by a back head and filling rim which has an opening therein for the reception or withdrawal o an inner cylindrical shell which forms one wall of a fire b'ox,.the rear end of which is enclosed by two heads forming a water wall, holes being provided in the inner shell for the circulation of water between the heads, the front end of the inner saell being closed by a tube sheet, and having fire tubes and stays extending forward therefron to the first named tube sheet, the inner and outer shells being spaced apart and having a portion of their bottoms removed for a grate opening,

a grate in said opening, and a mud frame box, and fire tubes 1 secured between said shells around the edges of said opening, said inner shell being of uniform diameter throughout its length and having its longitudinal axial center extending below the longitudinal axial center of said outer shell and smoke box.

6. The combination with a boiler comprising an outer cylindrical shell having its forward end enclosed by a tube sheet, which also forms the rear wall of a smoke box having a stack therein, the rear end of said shell being enclosed by a back head and a filling rim which has an opening therein for the reception or withdrawal of an inner cylindrical shell which forms one wall of a fire box, the rear end of which is closed by two heads forming a water wall, holes being provided in the inner shell for the circulation of water between the heads, the front end of the inner shell being closed by a tube sheet and having fire tubes and stays extending forward therefrom to the first named tube sheet, the inner and outer shells being spaced apart and having a portion of their bottoms removed for agrate opening, a grate in said opening. and a mud frame secured between said shells around the edges of said opening, saidinnershell being uniform in diameter for its entire length and having its longitudinal axial center extending below the longitudinal axial Center of said outer shell and said smoke box, said inner shell resting on said mud frame and being extended forward its full diametera distance from said grate opening, water tubes extending through said inner shell above and around each side of the longitudinal axial center of said boiler shell arranged in circular and'radial alignment and secured at their front ends to the tube sheet of the inner shell, and at their rear ends to the inner head of said rear water wall. I

7. The combination with a boiler comprising an outer cylindrical shell having its forward end closed by a tube sheet, which also forms the rear wall of a smoke box having a stack therein, the rear end of said shell being enclosed by a back head and a filling rim which has an opening therein for the reception or withdrawal of an inner cylindrical shell which forms one wall of a fire box, the rear end of which is enclosed by two heads forming a water wall, holes being provided in the inner shell for the circulation of water between the heads, the front end of the inner shell being closed by a tube sheet, and having fire tubes and stays extending forward therefrom to the first named tube sheet, the inner and outer shells being spaced apart and having a portion of their bottoms removed for a grate opening, a grate in said opening, and a mud frame secured between said shells around the or of said opening, said inner shell being uniform in diameter for entire length and having its longitudinal axial center extend ed below the longitudinal axial center of said outer shell and said smoke box, said inner shell resting on said mud frame and being extended forward its full diameter a distance from said grate opening, said fire tubes extending from the longitudinal axial center of the boiler and smoke box downward to the bottom of the tube sheet of the fire box, stays extending between said tube sheets and secured thereto in alignment above said fire tubes, connection head means being provided in said smoke box for connecting a cylindrical shell superheater of less diameter than said boiler shell and of different diameters at different elevations, said superheater shell having three tube sheets spaced apart therein, fire tubes extending through and secured thereto forming a water wall between the snperheating section and said smoke box, and said fire tubes communicating with said smoke box and another smoke box having a discharge stack in advance of said superheater.

8. The combination with a boiler having an ordinary smoke box and stack at its for ward end, an ordinary boiler shell and open bottom fire box at its rear end, a grate in said opening, a second smoke box and stack between the first mentioned smoke box and the fire box, fire tubes extending between said second smoke box and the fire box, of a cylindrical shell superheater of less diameter than said boiler shell and having three tube sheets spaced apart therein, and fire tubes extending through and secured to each of said tube sheets, forming a superheating section in the forward end of said shell and a water wall in the rear end thereof, said superheater extending between and forming a wall of each of said smoke boxes, and connection head means being provided in said second smoke box for connecting said front smoke box and superheater sections of various smaller diameters than said boiler shell or at different elevations.

CHARLES WAKEFIELD CROWELL. 

